Incandescent electric lamp.



Patented lune II,

lnwnko'z.

L. LUBENTHAL.

INGANDESCENT ELECTRIC LAMP.

(Appheahon filed Apr 1 1901 (llo Model.)

UNITED STATES PATENT OFFICE.

L IVI LOBENTHAL, OF NElV YORK, N. Y., ASSIGNOR OF ELEVEN-TWENTIETIIS TOTHOMAS E. MCIVER, OF SAME PLACE, AND JOHN MCCULLOUGII, OF

NEWARK, NElV JERSEY.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 676,069, dated June 11,1901.

Application filed April 1, 1901. Serial No. 53,897. (No model.)

To aZZ whom it may concern: r

Be it known that I, LEVI LOBENTHAL, a citizen of the United States,residing in the borough of Manhattan, in the city, county, and

State of New York, have invented certain new and useful Improvements inincandescent Electric Lamps; and I do hereby declare the following to bea full, clear, and exact description of my invention, such as willenable oth- 1o ers skilled in the art to which it appertains to make anduse the same.

My invention has for its object to provide means whereby at will eitherof the filaments of a double-filament incandescent lamp may be throwninto circuit, and thus rendered luminous, without necessitating theremoval of the lamp from the socket, and whereby a lamp having thecapabilities above specified is adapted to be used in an ordinary formof socket, thereby permitting the replacement of a single-filament lampby my improved device Without necessitating any change in the fixtures.

For these purposes my invention consists in a new and useful form ofswitch for simultaneously throwing into circuit one of the two filamentsof the lamp and for throwing the other filament out of circuit, and itfurther consists in the construction, arrangement, and combination ofthe several parts of which it is composed, as will be hereinafter morefully described. and claimed.

Referring to the accompanying drawings, in which corresponding parts aredesignated by corresponding letters of reference, Figure 1 is a sideelevation, partly in section, of a lamp having my invention appliedthereto. Fig. 2 is a section on line 2 2 of Fig. 1, having adiagrammatic representation of the circuits. Fig. 3 is a perspectiveview of a base of a lamp having this invention applied thereto.

This invention is an improvement upon that described in anotherapplication filed by me in the United States Patent Office on the 11thday of October, 1900, and serially numbered 32,775. In the applicationabove named I contemplated an arrangement whereby what is therein termedthe primary filament could be used by itself or the primary andauxiliary filaments used together in multiple are with each other, or inthe case of the destruction of; the primary filament the auxiliaryfilament could be used by itself; but in this my presentinvention I havetwo filaments either of which can at any time be brought into thecircuit and rendered luminous, but both of which cannot be brought intothe circuit at the same time. By this means either filament can be usedby itself irrespective of the condition of the other filament, so thatif one of the filaments be of greater candlepower than the other it willbe possible by manipulation of the switching mechanism hereinafterdescribed to throw into the circuit that filament having the desiredcandlepower. \Vhile I have therefore shown two filaments a and I) of myimproved lamp of similar construction it will be understood that ifdesired one filament may be of greater candle-power than the other,although this is not necessary, as by the use of two identical filamentsthe advantage is obtained of practi cally doubling the life of the lamp.

One end of each of the filaments a and b is connected with a leading-inWire 0, connected with the cap or plate d on the base of the lamp, theopposite terminals of the filaments, which will hereinafter be termedthe outer terminals, being connected with the leadingin wires a and b,respectively.

The base of the lamp-bulb is surrounded with a collar 6 of the usualconstruction, except as hereinafterspecified, the collar being adaptedto be received in any appropriate form of socket. A washer f ofinsulating material, such as indurated fiber, is interposed between theneck of the collar and the lamp-bulb and carries thereon twocontactplates at and b adjacent to but insulated from each other, thesaid plates resting in a notch g in the top of the collar and the outersurface of the plates being flush with the surface of the neck of thecollar. The leading-in Wires a and I) pass upwardly between the outersurface of the lamp-bulb and the washer f and are connected to thecontact-plates a and b respectively.

The neck of the collar has ears h struck up thereon and adapted toreceive a split ring 1', provided with a handle portion 1', the openingin the split ring being substantially equal to the conjoint width of thecontact-plates and the Width of the insulating space between them,whereby as the ring is rotated in its guiding-ears either one of thecontact-plates may be brought into electrical connection with thecollar. The electrical connection of the ring with the contact-plate ais shown in dotted lines in Fig. 2, whereas if the ring he in theposition shown in full lines in that figure the connection will be withthe contact-plate 6 The exact width of the opening in the ring may bevaried, but I prefer that it be of the width before given, as thereby itis rendered impossible to simultaneously throw the full current strengththrough both filaments in multiple (this being due to the resistance ofthe slight contact area in circuit at that time) or to entirely out outboth filaments at the same time by a movement of the ring.

In order to prevent the rotation of the ring to an extent to cause it tosimultaneously and fully connect both contact-plates with the collar,the guide-ears h for the ring are so disposed as to serve as limit-stopsfor the handle portion of the ring, thus preventing the movement of thelatter beyond the positions shown in Fig. 2.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent of the United States, is

1. In an incandescent electric lamp, the combination with a bulb, of twofilaments, a slotted collar surrounding the base of the bulb, twocontact-plates located in the slots in the collar, insulated from eachother and connected with the outer terminal of the filaments and arotating ring mounted upon the said collar and adapted to make contactbetween either of the said plates and the collar, substantially asdescribed.

2. In a double-filament incandescent electric lamp, the combination of aslotted collar surrounding the base of the lamp, a plurality ofcontact-plates located in the slots of the collar, insulated from eachother and connected with the terminals of the filaments of the lamp, arotating ring mounted upon the said collar and adapted to make contactbetween either of the said plates and the collar, and means forpreventing the movement of the ring, substantially as'described.

3. In an incandescent electric lamp, the combination with a globe of twofilaments, a plate connected to the corresponding terminals of the saidfilaments, a slotted collar surrounding the base of the bulb, aplurality of contact-plates located in the slots of the collar adjacentto, but insulated from, each other, and connected to the terminals ofthe filaments, and a ring mounted on the collar and having an openportion, of a proper are to bridge either of the said contact-plates,according to its position, substantially as described.

4. In a double-filament incandescent electric lamp, the combination witha globe of two filaments, a plate connected to the correspondingterminals ot both of the said filaments, a slotted collar surroundingthe base of the bulb, a plurality of contact-plates lo cated in theslots of the collar adjacent to, but insulated from, each other, andconnected to the terminals of the filaments, and a ring mounted on thecollar having an open portion of a width substantially equal to theconjoint width of the contact-plates and the space between them,substantially as described.

In testimony whereof I have hereunto set my hand this 28th day of March,1901.

LEVI LOBENTHAL.

Witnesses:

CHRISTOPHER A. MAY, HENRY (J. GoTTEsMAN.

